JPH0895317A - Image forming device - Google Patents
Image forming deviceInfo
- Publication number
- JPH0895317A JPH0895317A JP6233121A JP23312194A JPH0895317A JP H0895317 A JPH0895317 A JP H0895317A JP 6233121 A JP6233121 A JP 6233121A JP 23312194 A JP23312194 A JP 23312194A JP H0895317 A JPH0895317 A JP H0895317A
- Authority
- JP
- Japan
- Prior art keywords
- correction
- image forming
- temperature
- potential
- photoconductor
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
Classifications
-
- G—PHYSICS
- G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
- G03G—ELECTROGRAPHY; ELECTROPHOTOGRAPHY; MAGNETOGRAPHY
- G03G15/00—Apparatus for electrographic processes using a charge pattern
- G03G15/02—Apparatus for electrographic processes using a charge pattern for laying down a uniform charge, e.g. for sensitising; Corona discharge devices
- G03G15/0266—Arrangements for controlling the amount of charge
-
- G—PHYSICS
- G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
- G03G—ELECTROGRAPHY; ELECTROPHOTOGRAPHY; MAGNETOGRAPHY
- G03G15/00—Apparatus for electrographic processes using a charge pattern
- G03G15/04—Apparatus for electrographic processes using a charge pattern for exposing, i.e. imagewise exposure by optically projecting the original image on a photoconductive recording material
- G03G15/043—Apparatus for electrographic processes using a charge pattern for exposing, i.e. imagewise exposure by optically projecting the original image on a photoconductive recording material with means for controlling illumination or exposure
-
- G—PHYSICS
- G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
- G03G—ELECTROGRAPHY; ELECTROPHOTOGRAPHY; MAGNETOGRAPHY
- G03G2215/00—Apparatus for electrophotographic processes
- G03G2215/02—Arrangements for laying down a uniform charge
- G03G2215/021—Arrangements for laying down a uniform charge by contact, friction or induction
Landscapes
- Physics & Mathematics (AREA)
- General Physics & Mathematics (AREA)
- Engineering & Computer Science (AREA)
- Plasma & Fusion (AREA)
- Electrostatic Charge, Transfer And Separation In Electrography (AREA)
- Control Or Security For Electrophotography (AREA)
Abstract
Description
【0001】[0001]
【産業上の利用分野】この発明は、レーザプリンタ,複
写機,ファクシミリ装置等の静電写真方式の画像形成装
置に関し、特に回動する感光体に帯電部材を接触させて
その表面を帯電させるようにした画像形成装置に関す
る。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electrostatic photography type image forming apparatus such as a laser printer, a copying machine, a facsimile machine, etc., and more particularly, a charging member is brought into contact with a rotating photosensitive member to charge its surface. The present invention relates to an image forming apparatus.
【0002】[0002]
【従来の技術】複写機等の静電写真方式の画像形成装置
においては、ドラム状あるいはベルト状の感光体の表面
を帯電器によって一様に帯電させた後、露光装置によっ
て露光して静電潜像を形成し、その潜像を現像器内の現
像ローラによってトナーを付着させて顕像化した後、転
写装置により給紙部から給紙される転写紙に転写し、そ
れを定着器によって定着して排出すると共に、感光体の
表面の残留トナーをクリーニング装置によって除去する
ようにしている。2. Description of the Related Art In an electrostatic image forming apparatus such as a copying machine, the surface of a drum-shaped or belt-shaped photosensitive member is uniformly charged by a charger and then exposed by an exposure device to be electrostatically charged. A latent image is formed, and the latent image is visualized by attaching toner with a developing roller in a developing device, and then transferred to a transfer paper fed from a paper feeding section by a transfer device, and then transferred by a fixing device. The toner is fixed and discharged, and the residual toner on the surface of the photoconductor is removed by a cleaning device.
【0003】ところで、従来の静電写真方式の画像形成
装置では、感光体を一様に帯電させるために非接触方式
であるコロナ放電方式が用いられてきたが、これは放電
空間をイオン化して感光体を帯電させるため多量のオゾ
ンが発生していた。このオゾンはマイナス放電を行なっ
た場合により多く発生するが、近年感光体がマイナス帯
電用の有機感光体になってきたことや発生ガスに対する
環境基準が厳しくなってきたことと併せて深刻な問題と
なっている。また、オゾンによって2次的に生成される
窒素酸化物(NOx)等の放電器への付着により、帯電
ムラを引き起こす等の問題もある。By the way, in a conventional electrostatic image forming apparatus, a corona discharge method which is a non-contact method has been used in order to uniformly charge a photosensitive member. A large amount of ozone was generated to charge the photoconductor. This ozone is generated more often when a negative discharge is performed, but it is a serious problem along with the fact that the photoreceptor has become an organic photoreceptor for negative charging in recent years and the environmental standard for generated gas has become strict. Has become. Further, there is also a problem that non-uniform charging is caused by adhesion of nitrogen oxides (NOx) secondarily generated by ozone to the discharger.
【0004】そこで、これらの問題を解消するため、近
年感光体の表面に電圧を印加した帯電ローラ等の帯電部
材を接触させて、感光体の表面を帯電する接触帯電方式
の画像形成装置が開発されている。この画像形成装置で
は、感光体の表面を帯電部材との間に存在する空隙を通
した放電によって帯電させるため、コロナ放電と比較し
て印加電圧が低くでき、オゾン発生量が激減するという
利点を持つ。Therefore, in order to solve these problems, a contact charging type image forming apparatus has recently been developed in which a charging member such as a charging roller to which a voltage is applied is brought into contact with the surface of the photoconductor to charge the surface of the photoconductor. Has been done. In this image forming apparatus, since the surface of the photoconductor is charged by the discharge through the gap existing between the photoconductor and the charging member, the applied voltage can be lowered as compared with the corona discharge, and the ozone generation amount is drastically reduced. To have.
【0005】[0005]
【発明が解決しようとする課題】しかしながら、このよ
うな画像形成装置においては、使用環境により帯電部材
の抵抗値や誘電率が変化するため必要な帯電電位が得ら
れず、帯電ムラの原因になっていた。そこで、特開平4
−186381号公報に見られるように、帯電部材の温
度を検出し、その検出温度によって帯電部材に印加する
電圧を可変させることにより、帯電ムラを防止するよう
にしたものが提案されているが、感光体の表面電位の温
度依存性は帯電部材の印加電圧に対して比例しないた
め、帯電ムラを完全に防止するのは難しい。However, in such an image forming apparatus, the required charging potential cannot be obtained because the resistance value and the dielectric constant of the charging member change depending on the environment of use, which causes uneven charging. Was there. Therefore, JP-A-4
As disclosed in Japanese Patent Application Laid-Open No. 186381, there has been proposed one in which uneven charging is prevented by detecting the temperature of the charging member and varying the voltage applied to the charging member according to the detected temperature. Since the temperature dependence of the surface potential of the photoconductor is not proportional to the voltage applied to the charging member, it is difficult to completely prevent uneven charging.
【0006】また、感光体の感光膜の摩擦により生じる
感光層の膜減りに起因して、感光体の帯電電位が変動す
るという問題もある。そこで、特開平5−27557号
公報に見られるように、感光体の膜減り量を検知し、そ
の量の増加に応じて帯電部材への印加電圧を下げること
により、感光体の帯電電位を所定値に保つようにしたも
のが提案されているが、感光体の膜減りの影響は高温時
と低温時で逆になるため、常に帯電電位を一定値に保つ
ことはできない。There is also a problem that the charging potential of the photoconductor fluctuates due to film loss of the photoconductive layer caused by friction of the photoconductive film of the photoconductor. Therefore, as disclosed in Japanese Patent Application Laid-Open No. 5-27557, the amount of film loss of the photoconductor is detected, and the voltage applied to the charging member is lowered in accordance with the increase in the amount, whereby the charging potential of the photoconductor is set to a predetermined value. Although it has been proposed to keep the value at a constant value, the effect of film loss of the photoconductor is opposite at high temperature and at low temperature, so the charging potential cannot always be kept at a constant value.
【0007】さらに、帯電部材として帯電ローラを用い
る場合、その帯電ローラは小型化の目的で感光体よりも
はるかに小径のものが用いられるのが一般的であるた
め、画像上では問題とならないようなクリーニング装置
を通過したわずかなトナーの付着による汚れも、付着頻
度が増えることによって大きな汚れとなり、部分的な帯
電不良を起こす原因になっていた。Further, when a charging roller is used as the charging member, the charging roller generally has a diameter much smaller than that of the photosensitive member for the purpose of downsizing, so that it does not pose a problem on the image. Even a small amount of dirt that adheres to the toner after passing through such a cleaning device becomes a large dirt due to an increase in the frequency of adhesion, causing a partial charging failure.
【0008】この発明は上記の点に鑑みてなされたもの
であり、使用環境や経時変動に係わらず感光体の帯電電
位を常に一定値に保持し、画像品質の安定化を図ること
を目的とする。The present invention has been made in view of the above points, and it is an object of the present invention to always maintain the charging potential of a photosensitive member at a constant value regardless of the use environment and the temporal change, and to stabilize the image quality. To do.
【0009】[0009]
【課題を解決するための手段】この発明は上記の目的を
達成するため、回動する感光体と、感光体に接触してそ
の表面を一様に帯電させる帯電部材と、帯電部材によっ
て帯電された感光体の表面を露光して静電潜像を形成す
る露光装置と、その潜像を現像ローラによりトナーを付
着させて顕像化する現像器と、その顕像化されたトナー
像を転写紙に転写する転写装置と、帯電部材の表面をク
リーニングするクリーニング部材とを備えた静電写真方
式の画像形成装置において、以下の各手段を設けたもの
である。In order to achieve the above-mentioned object, the present invention achieves the above object, a photoconductor that rotates, a charging member that contacts the photoconductor to uniformly charge the surface thereof, and a charging member that charges the surface. An exposure device that exposes the surface of the photoconductor to form an electrostatic latent image, a developing device that visualizes the latent image by attaching toner with a developing roller, and the visualized toner image is transferred. An electrophotographic image forming apparatus including a transfer device for transferring onto paper and a cleaning member for cleaning the surface of a charging member is provided with the following respective means.
【0010】すなわち、図1の機能ブロック図に示すよ
うに、帯電部材の温度を検知する温度検知手段Aと、感
光体の経時変化を検知する経時変化検知手段Bと、温度
検知手段Aの検知温度に応じて帯電部材への印加電圧を
補正する印加電圧補正手段Cと、該手段Cによる上記検
知温度に応じた印加電圧の補正ルールを経時変化検知手
段Bによって検知された経時変化量に応じて切り換える
補正ルール切換手段Dと、印加電圧補正手段Cによって
補正した電圧を帯電部材に印加することにより感光体の
表面を帯電した後、露光装置によって露光して基準電位
パターンを形成し、その電位を検知して作像プロセス時
の露光装置の光量を補正する光量補正手段Eとを設けた
ものである。That is, as shown in the functional block diagram of FIG. 1, temperature detecting means A for detecting the temperature of the charging member, time-dependent change detecting means B for detecting the time-dependent change of the photosensitive member, and temperature detecting means A for detecting. The applied voltage correction means C for correcting the applied voltage to the charging member according to the temperature, and the correction rule of the applied voltage according to the detected temperature by the means C are provided according to the amount of change with time detected by the change with time detecting means B. After the surface of the photoconductor is charged by applying the voltage corrected by the correction rule switching means D and the applied voltage correction means C to the charging member, the exposure device exposes the reference potential pattern to form the potential. And a light quantity correction means E for detecting the light quantity and correcting the light quantity of the exposure device during the image forming process.
【0011】また、印加電圧補正手段Cによって補正し
た電圧を帯電部材に印加することにより感光体の表面を
帯電した後除電し、その残留電位を検知して作像プロセ
ス時の感光体表面の帯電電位あるいは現像ローラの現像
バイアスを補正する電位補正手段Fを設けるとよい。Further, the voltage corrected by the applied voltage correction means C is applied to the charging member to charge the surface of the photoconductor and then the charge is removed, and the residual potential is detected to charge the surface of the photoconductor during the image forming process. It is preferable to provide a potential correction means F for correcting the potential or the developing bias of the developing roller.
【0012】さらに、補正ルール切換手段Dを、画像形
成ジョブ終了後に経時変化検知手段Bによって検知され
た経時変化量が予め定めた所定量を上回った場合に、印
加電圧補正手段Cによる上記検知温度に応じた印加電圧
の補正ルールを切り換える手段とし、印加電圧補正手段
Cを、補正ルール切換手段Dによる補正ルールの切り換
えが行なわれた後、その補正ルールを参照して温度検知
手段Aの検知温度に応じて帯電部材への印加電圧を補正
する手段とするようにすればよい。Further, in the correction rule switching means D, when the time-dependent change amount detected by the time-dependent change detecting means B after the completion of the image forming job exceeds a predetermined amount, a temperature detected by the applied voltage correcting means C is detected. The means for switching the correction rule of the applied voltage according to the above, the applied voltage correction means C is used to switch the correction rule by the correction rule switching means D, and then the detected temperature of the temperature detection means A is referred to with reference to the correction rule. Therefore, a means for correcting the voltage applied to the charging member may be used.
【0013】さらにまた、光量補正手段E及び電位補正
手段Fによる補正処理が行なわれる前に、クリーニング
部材によって帯電部材をクリーニングする手段を設ける
ことが望ましい。また、温度検知手段Aの検知温度が予
め定めた閾値を下回った場合に、クリーニング部材によ
って帯電部材をクリーニングする手段を設けるとよい。Furthermore, it is desirable to provide a means for cleaning the charging member with a cleaning member before the correction processing by the light amount correction means E and the potential correction means F is performed. Further, it is preferable to provide a means for cleaning the charging member with the cleaning member when the temperature detected by the temperature detecting means A falls below a predetermined threshold value.
【0014】さらに、光量補正手段E及び電位補正手段
Fが、温度検知手段Aの検知温度が予め定めた閾値を下
回った場合、あるいは予め定めた閾値を下回った後該閾
値を上回った場合に上記補正処理を行なうようにすれば
よい。Further, when the light amount correcting means E and the potential correcting means F detect the temperature detected by the temperature detecting means A below a predetermined threshold value, or when the detected temperature exceeds the predetermined threshold value after the temperature falls below the predetermined threshold value. A correction process may be performed.
【0015】[0015]
【作用】この発明の画像形成装置では、図1の補正ルー
ル切換手段Dが経時変化検知手段Bによって検知された
経時変化量に応じて印加電圧補正手段Cによる補正ルー
ルを切り換え、印加電圧補正手段Cがその補正ルールを
参照して温度検知手段Aの検知温度に応じて帯電部材へ
の印加電圧を補正し、その補正した電圧の帯電部材への
印加により感光体の表面を帯電した後、光量補正手段E
が露光装置によって露光して基準電位パターンを形成
し、その電位を検知して作像プロセス時の露光装置の光
量を補正するので、例えばセレン系の感光体を使用して
いる場合には、機内環境(使用環境)や経時変動に係わ
らずその感光体の帯電電位を常に一定値に保持でき、安
定した画像品質を得られる。In the image forming apparatus of the present invention, the correction rule switching means D of FIG. 1 switches the correction rule by the applied voltage correction means C in accordance with the amount of change over time detected by the change detection means B, and the applied voltage correction means. C corrects the voltage applied to the charging member according to the temperature detected by the temperature detecting means A by referring to the correction rule, and charges the surface of the photoconductor by applying the corrected voltage to the charging member. Correction means E
Forms a reference potential pattern by exposing with an exposure device, and detects the potential to correct the light amount of the exposure device during the image forming process.For example, when a selenium-based photoconductor is used, Regardless of the environment (usage environment) or the change over time, the charged potential of the photoconductor can always be maintained at a constant value, and stable image quality can be obtained.
【0016】また、電位補正手段Fにより、印加電圧補
正手段Cによって補正した電圧を帯電部材に印加するこ
とにより感光体の表面を帯電した後除電し、その残留電
位を検知して作像プロセス時の感光体表面の帯電電位あ
るいは現像ローラの現像バイアスを補正するようにすれ
ば、OPC(有機光導電体)系の感光体を使用した場合
でも、上述と同様に機内環境や経時変動に係わらずその
感光体の帯電電位を常に一定値に保つことができる。Further, the potential correction means F applies the voltage corrected by the applied voltage correction means C to the charging member to charge the surface of the photosensitive member and then removes the charge, and the residual potential is detected to perform the image forming process. If the charge potential on the surface of the photoconductor or the developing bias of the developing roller is corrected, even when an OPC (organic photoconductor) -based photoconductor is used, the same as the above, regardless of the in-machine environment and the temporal change. The charging potential of the photoconductor can be always maintained at a constant value.
【0017】さらに、画像形成ジョブ終了後に経時変化
検知手段Bによって検知された経時変化量が予め定めた
所定量を上回った場合に、補正ルール切換手段Dが印加
電圧補正手段Cによる補正ルールを切り換え、その後印
加電圧補正手段Cがその補正ルールを参照して温度検知
手段Aの検知温度に応じて帯電部材への印加電圧を補正
するようにすれば、上記補正ルールが切り換えられた時
でも感光体の帯電電位は変化することがないため、より
安定した画像品質を得られる。Further, when the temporal change amount detected by the temporal change detecting means B after the image forming job is over a predetermined amount, the correction rule switching means D switches the correction rule by the applied voltage correcting means C. If the applied voltage correction means C then corrects the applied voltage to the charging member according to the temperature detected by the temperature detection means A with reference to the correction rule, the photoconductor will be activated even when the correction rule is switched. Since the charging potential of 1 does not change, more stable image quality can be obtained.
【0018】さらにまた、光量補正手段E及び電位補正
手段Fによる補正処理を行なう前に、クリーニング部材
によって帯電部材をクリーニングするようにすれば、帯
電部材がトナーで汚れることがなくなるため帯電不良が
低減し、より一層安定した画像品質を得られる。また、
温度検知手段Aの検知温度が予め定めた閾値を下回った
場合に、クリーニング部材によって帯電部材をクリーニ
ングするようにすれば、新たな機構によって機内環境を
検知することなく、安価な構成で環境変動による帯電部
材の汚れを効果的に防止することができる。Furthermore, if the charging member is cleaned by the cleaning member before the correction processing by the light amount correcting means E and the potential correcting means F is performed, the charging member is prevented from being contaminated with the toner and the charging failure is reduced. In addition, a more stable image quality can be obtained. Also,
If the cleaning member cleans the charging member when the temperature detected by the temperature detecting means A falls below a predetermined threshold value, a new mechanism does not detect the in-machine environment, and the environment changes due to an inexpensive configuration. It is possible to effectively prevent the charging member from being soiled.
【0019】さらに、光量補正手段E及び電位補正手段
Fが、温度検知手段Aの検知温度が予め定めた閾値を下
回った場合に上記補正処理を行なうようにすれば、低温
時における感光体の感度の低下によって画像が暗目にシ
フトするのを防止できる。あるいは、光量補正手段E及
び電位補正手段Fが、温度検知手段Aの検知温度が予め
定めた閾値を下回った後該閾値を上回った場合に上記補
正処理を行なうようにすれば、機内環境の変化による画
像の変動を防止できる。Further, if the light amount correction means E and the potential correction means F perform the above correction processing when the temperature detected by the temperature detection means A falls below a predetermined threshold value, the sensitivity of the photoconductor at a low temperature. It is possible to prevent the image from being shifted to the dark side due to the decrease of. Alternatively, if the light quantity correction means E and the potential correction means F perform the above correction processing when the temperature detected by the temperature detection means A exceeds a predetermined threshold value and then exceeds the threshold value, the change in the in-machine environment It is possible to prevent image fluctuation due to
【0020】[0020]
【実施例】以下、この発明の実施例を図面に基づいて具
体的に説明する。図2は、この発明の一実施例である複
写機のドラム回りを示す概略構成図である。DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT An embodiment of the present invention will be specifically described below with reference to the drawings. FIG. 2 is a schematic configuration diagram showing the periphery of a drum of a copying machine which is an embodiment of the present invention.
【0021】この複写機は、被帯電体であるドラム状の
回転する感光体1に帯電部材である帯電ローラ2を直接
接触させた状態で、そこに予め設定された電圧を印加し
て感光体1の表面1aを所定の電位に一様に帯電する接
触帯電方式の複写機であり、感光体1が矢示A方向に所
定の周速度で回転し、それに帯電ローラ2が接触しなが
ら連れ回りにより矢示方向に等速で従動回転する。In this copying machine, a photosensitive drum 1 which is a member to be charged is directly contacted with a charging roller 2 which is a charging member and a preset voltage is applied to the photosensitive member 1 so that the photosensitive member 1 is rotated. 1 is a contact charging type copier that uniformly charges the surface 1a of the photosensitive drum 1 to a predetermined potential, and the photoconductor 1 rotates in the direction of arrow A at a predetermined peripheral speed, and the charging roller 2 rotates while making contact with it. Will rotate at a constant speed in the direction of the arrow.
【0022】感光体1は、ドラム駆動タイミングベル
ト,ドラム駆動プーリ,それらを駆動するモータ(いず
れも図示を省略している)等からなる駆動装置によって
駆動され、その表面1aには常に帯電ローラ2が所定の
圧力で接触している。その感光体1の回りには、帯電ロ
ーラ2の他に、イレーサ3,現像器4,無端ベルト7a
を有する接触型の転写装置7,Pセンサ8,クリーニン
グユニット9,クエンチングランプ10が順次配設され
ている。The photosensitive member 1 is driven by a driving device including a drum driving timing belt, a drum driving pulley, a motor (not shown) for driving the drum driving pulley, etc., and the charging roller 2 is always provided on the surface 1a. Are in contact with each other with a predetermined pressure. Around the photoconductor 1, in addition to the charging roller 2, the eraser 3, the developing device 4, the endless belt 7a.
A contact type transfer device 7, a P sensor 8, a cleaning unit 9, and a quenching lamp 10 are sequentially arranged.
【0023】そして、通常の作像プロセス時には、帯電
ローラ2によって感光体1の表面1aを所定の電位(こ
の例では−900V)に帯電した後、その帯電面を露光
装置11(ミラー部分のみ図示している)からの原稿画
像に応じた光によって露光して静電潜像を形成し、その
静電潜像をイレーサ3によって使用される転写紙Pのサ
イズより外側の領域部分の静電荷を除去(トリミング)
し、その残った静電潜像を現像器4の現像ローラ(現像
スリーブ)4aによって供給されるトナーにより可視像
化(現像)する。In a normal image forming process, the surface 1a of the photosensitive member 1 is charged by the charging roller 2 to a predetermined potential (-900 V in this example), and the charged surface is exposed by the exposure device 11 (only the mirror portion is shown in FIG. (Shown) to form an electrostatic latent image by exposure to light corresponding to the original image from the original image, and the electrostatic latent image is subjected to electrostatic charge in an area portion outside the size of the transfer paper P used by the eraser 3. Removal (trimming)
Then, the remaining electrostatic latent image is visualized (developed) by the toner supplied by the developing roller (developing sleeve) 4a of the developing device 4.
【0024】一方、給紙カセット(図示せず)内の転写
紙を、所定のタイミングで回転する給紙ローラにより1
枚ずつ送り出し、それをレジストローラ12とそれに圧
接回転する加圧ローラ13との間で一旦停止させてタイ
ミング調整を行なった後、感光体1上のトナー像と一致
する正確なタイミングで転写装置7が設けられている転
写部に向けて給送する。On the other hand, the transfer paper in the paper feed cassette (not shown) is moved by a paper feed roller which rotates at a predetermined timing.
The image is sent out one by one, and is temporarily stopped between the registration roller 12 and the pressure roller 13 that rotates in pressure contact with the registration roller 12 to adjust the timing, and then the transfer device 7 is set at an accurate timing that matches the toner image on the photoconductor 1. The sheet is fed toward the transfer section where is provided.
【0025】そして、その転写紙Pに転写装置7によっ
て転写バイアスを印加して図2で上面側にトナー像を転
写し、それを感光体1から分離させて図示しない定着装
置へ搬送して、そこでトナー像を熱定着した後に装置外
部の排紙トレイ等へ排出させる。Then, a transfer bias is applied to the transfer paper P by the transfer device 7 to transfer the toner image on the upper surface side in FIG. 2, and the toner image is separated from the photoconductor 1 and conveyed to a fixing device (not shown). Therefore, the toner image is thermally fixed and then discharged to a discharge tray or the like outside the apparatus.
【0026】また、その転写終了後に感光体1上に残っ
た残留トナー及び紙粉等の異物を、クリーニングユニッ
ト9に設けられているクリーニングブレード9aにより
取り除き、その感光体1上に残った残留電位をクエンチ
ングランプ10(除電装置)により取り除いて、次の帯
電ローラ2による帯電に備え、再び一連の作像プロセス
を繰り返す。Further, the residual toner remaining on the photosensitive member 1 after the transfer is removed by a cleaning blade 9a provided in the cleaning unit 9, and the residual potential remaining on the photosensitive member 1 is removed. Is removed by the quenching lamp 10 (static elimination device), and a series of image forming processes are repeated again in preparation for the next charging by the charging roller 2.
【0027】図3は、図2の主要部分を制御系と共に示
す図である。この図において、2は上述した帯電ローラ
であり、鉄等からなる導電性芯金21の外側にエピクロ
ルヒドリンゴムよりなる弾性層22を装着し、その弾性
層22上にルミフロンにヒドリンゴムを分散させた表面
層23を塗工した構成のものを用いている。FIG. 3 is a diagram showing a main part of FIG. 2 together with a control system. In this figure, 2 is the charging roller described above, and an elastic layer 22 made of epichlorohydrin rubber is attached to the outside of a conductive cored bar 21 made of iron or the like, and a surface of the elastic layer 22 on which hydrin rubber is dispersed in Lumiflon. The structure in which the layer 23 is applied is used.
【0028】24は図1に示した温度検知手段Aに相当
する温度検知部であり、導電性板バネ25の先端部分に
温度検知素子(例えばサーミスタ)26が固着され、そ
の温度検知素子26が図示しないフィルム材を介して帯
電ローラ2の表面に接触されており、その温度を検知し
て制御装置31へ知らせる。27はクリーニング部材で
あり、通常は帯電ローラ2から離間しており、制御装置
31による後述するこの発明に係わる処理時に、図示し
ない駆動装置により所定のタイミングで帯電ローラ2に
接触してその表面をクリーニングする。Reference numeral 24 is a temperature detecting portion corresponding to the temperature detecting means A shown in FIG. 1. A temperature detecting element (for example, a thermistor) 26 is fixed to the tip of the conductive leaf spring 25, and the temperature detecting element 26 is attached. It is in contact with the surface of the charging roller 2 via a film material (not shown), and the temperature thereof is detected and notified to the control device 31. Reference numeral 27 denotes a cleaning member, which is normally separated from the charging roller 2 and contacts the charging roller 2 at a predetermined timing by a driving device (not shown) at a predetermined timing during a process according to the invention described later by the control device 31. To clean.
【0029】制御装置31は汎用のマイクロコンピュー
タであり、この複写機内の各部を統括的に制御する。な
お、この制御装置31が図1に示した印加電圧補正手段
C,補正ルール切換手段D,光量補正手段E,及び電位
補正手段Fとしての機能も果たす。32は電圧印加装置
であり、所定のタイミングで帯電ローラ2の導電性芯金
21に電圧を印加し、それによって感光体1の表面1a
が一様に帯電される。The control device 31 is a general-purpose microcomputer and controls each part in the copying machine as a whole. The control device 31 also functions as the applied voltage correction means C, the correction rule switching means D, the light quantity correction means E, and the potential correction means F shown in FIG. A voltage application device 32 applies a voltage to the conductive cored bar 21 of the charging roller 2 at a predetermined timing, whereby the surface 1a of the photoconductor 1 is applied.
Are uniformly charged.
【0030】33は図1に示した経時変化検知手段Bに
相当する経時変化検知装置33であり、感光体1の経時
変化を検知して制御装置31に知らせる。この実施例で
は、感光体1の経時変化をその積算回転時間とし、それ
をタイマ/カウンタを用いて計測(検知)するものとす
る。Reference numeral 33 denotes a time-dependent change detecting device 33 corresponding to the time-dependent change detecting means B shown in FIG. 1, which detects a change with time of the photoconductor 1 and notifies the control device 31 of the change. In this embodiment, it is assumed that the change over time of the photoconductor 1 is its accumulated rotation time and that it is measured (detected) using a timer / counter.
【0031】ここで、この実施例においては、例えば予
め設定された枚数のコピー(作像プロセス)が終了する
毎に、Pセンサ8によるトナー濃度制御を行なう。すな
わち、図示しない駆動装置によって転写装置7の無端ベ
ルト7aを感光体1の表面1aから離間させた後、帯電
ローラ2によって感光体1の表面1aを所定の電圧(こ
の例では−600V)に帯電する。Here, in this embodiment, for example, the toner density control by the P sensor 8 is performed every time a preset number of copies (image forming process) are completed. That is, after the endless belt 7a of the transfer device 7 is separated from the surface 1a of the photoconductor 1 by a driving device (not shown), the surface 1a of the photoconductor 1 is charged by the charging roller 2 to a predetermined voltage (-600V in this example). To do.
【0032】次いで、露光装置11からの図示しないP
センサパターン板(濃度制御用パターンが形成された
板)で反射された光により露光して静電潜像を形成し、
その静電潜像を現像器4の現像ローラ4aによって可視
像化して濃度制御用パターン像を形成した後、そのトナ
ー付着量をフォトセンサ等からなるPセンサ8によって
測定し、その測定値が予め設定された値になるようにト
ナー補給装置14から現像器4へのトナーの補給を制御
した後、転写装置7の無端ベルト7aを感光体1の表面
1aに接触させる。Next, P (not shown) from the exposure apparatus 11
By exposing with the light reflected by the sensor pattern plate (the plate on which the density control pattern is formed), an electrostatic latent image is formed,
After the electrostatic latent image is visualized by the developing roller 4a of the developing device 4 to form a density control pattern image, the toner adhesion amount is measured by the P sensor 8 such as a photo sensor. After controlling the toner replenishment from the toner replenishing device 14 to the developing device 4 so that the value becomes a preset value, the endless belt 7a of the transfer device 7 is brought into contact with the surface 1a of the photoconductor 1.
【0033】また、帯電ローラ2の電気抵抗が機内温度
の変化によって大きく変化することと、感光体1の膜厚
(=感光体容量)の削れによって帯電電位が変化するた
め、制御装置31が温度検知部24及び経時変化検知装
置33の各検知値に基づいて電圧印加装置32による帯
電ローラ2への印加電圧を補正する等の各種処理を行な
うが、これらの処理については追って詳細に説明する。
ここでは、複写機で一般に行なわれるVR補正処理(残
留電位補正処理)及びVL補正処理(地肌電位制御)に
ついて簡単に説明しておく。Further, since the electric resistance of the charging roller 2 largely changes due to the change of the temperature inside the apparatus and the charging potential changes due to the film thickness of the photoconductor 1 (= photoconductor capacity) being scraped, the controller 31 controls the temperature. Various processings such as correcting the voltage applied to the charging roller 2 by the voltage application device 32 are performed based on the detection values of the detection unit 24 and the time-dependent change detection device 33. These processings will be described in detail later.
Here, the VR correction processing (residual potential correction processing) and the VL correction processing (background potential control) generally performed in the copying machine will be briefly described.
【0034】VR補正処理及びVL補正処理では、感光体
1上に形成した所定の電位パターン像のトナーの付着量
をPセンサ8によって測定する処理が含まれているた
め、転写装置7の無端ベルト7aが感光体1の表面1a
から離間されていなければならない。そこで、最初のV
R 補正処理で駆動装置により転写装置7の無端ベルト7
aを感光体1の表面1aから離間させ、その状態で以後
の処理を行なう。The VR correction process and the VL correction process include a process of measuring the toner adhesion amount of the predetermined potential pattern image formed on the photoconductor 1 by the P sensor 8, and therefore the endless belt of the transfer device 7 is included. 7a is the surface 1a of the photoreceptor 1.
Must be separated from. So the first V
In the R correction processing, the driving device drives the endless belt 7 of the transfer device 7.
a is separated from the surface 1a of the photoconductor 1, and the subsequent processing is performed in that state.
【0035】すなわち、帯電ローラ2によって感光体1
の表面1aを所定の電圧(この例では−900V)に帯
電した後、イレーサ3により除電して残留電位パターン
を形成し、それを現像器4の現像ローラ4a(現像バイ
アス=0V)によって可視像化した後、そのトナー付着
量をPセンサ8により測定することによって残留電位を
検知し、その結果に応じて作像プロセス時の感光体1表
面の帯電電位及び現像ローラ4aの現像バイアスを補正
する。つまり、残留電位が上昇した分だけ、帯電電位及
び現像バイアスを増加させる。That is, the photoreceptor 1 is charged by the charging roller 2.
After charging the surface 1a of the device to a predetermined voltage (-900V in this example), the eraser 3 removes the charge to form a residual potential pattern, which is visualized by the developing roller 4a (developing bias = 0V) of the developing device 4. After the image is formed, the toner adhesion amount is measured by the P sensor 8 to detect the residual potential, and the charge potential on the surface of the photoconductor 1 and the developing bias of the developing roller 4a during the image forming process are corrected according to the result. To do. That is, the charging potential and the developing bias are increased in proportion to the increase in the residual potential.
【0036】このVR 補正処理により、残留電位が上昇
しても、現像ローラ4aの現像バイアスと感光体1表面
の地肌電位との関係が常に(現像バイアス≫地肌電位)
になると共に、現像ポテンシャル(=帯電電位−現像バ
イアス)が一定になり、地肌汚れのない高IDの画像が
維持される。By this VR correction processing, even if the residual potential rises, the relationship between the developing bias of the developing roller 4a and the background potential of the surface of the photoconductor 1 is always (developing bias >> background potential).
As a result, the developing potential (= charging potential−developing bias) becomes constant, and an image of high ID free from background stain is maintained.
【0037】その後、VL 補正処理を行なう。つまり、
帯電ローラ2によって感光体1の表面1aを所定の電圧
(この例では−900V)に帯電した後、露光装置11
からの図示しないVL パターン板(低濃度の基準濃度パ
ターンが形成された板)で反射された光により露光して
基準電位パターンを形成し、それを現像器4の現像ロー
ラ4aによって可視像化した後、そのトナー付着量をP
センサ8によって測定することにより基準電位を検知
し、その結果が予め設定された値になるように作像プロ
セス時の露光装置11の露光ランプ電圧(光量)を制御
し、最後に転写装置7の無端ベルト7aを感光体1の表
面1aに接触させる。After that, VL correction processing is performed. That is,
After the surface 1a of the photoconductor 1 is charged to a predetermined voltage (-900V in this example) by the charging roller 2, the exposure device 11
Is exposed by light reflected by a VL pattern plate (a plate on which a low-density reference density pattern is formed) from FIG. 1 to form a reference potential pattern, which is visualized by the developing roller 4a of the developing device 4. After that, the toner adhesion amount is set to P
The reference potential is detected by measuring with the sensor 8, and the exposure lamp voltage (light amount) of the exposure device 11 during the image forming process is controlled so that the result becomes a preset value. The endless belt 7a is brought into contact with the surface 1a of the photoconductor 1.
【0038】このVL 補正処理により、中間調再現が一
定となり、安定した画像が維持される。ところで、上記
各補正処理はVR補正処理,VL補正処理の順番で行なわ
れるため、VL補正処理で感光体1上に基準電位パター
ン像(VLパターン像)を形成する際には、VR 補正処
理によって補正された帯電電位及び現像バイアスでその
作像を行なうことになる。その結果、画像における残留
電位の影響はさらに低減する。By this VL correction processing, the halftone reproduction becomes constant and a stable image is maintained. By the way, each of the above correction processes is performed in the order of the VR correction process and the VL correction process. Therefore, when the reference potential pattern image (VL pattern image) is formed on the photoconductor 1 by the VL correction process, the VR correction process is performed. The image is formed with the corrected charging potential and the developing bias. As a result, the effect of residual potential on the image is further reduced.
【0039】図4及び図5は、制御装置31によるこの
発明に係わる処理の一例を示すフローチャートである。
このルーチンはメインスイッチがONになったときにス
タートし、まずステップ1でフラグFragBを“0”に初
期化し、ステップ2で温度検知部24の検知温度が予め
定めた第2の設定温度T2 (この例では20℃)より低
いかどうかを判断する。FIGS. 4 and 5 are flow charts showing an example of the processing according to the present invention by the control device 31.
This routine starts when the main switch is turned on. First, in step 1, the flag FragB is initialized to "0", and in step 2, the temperature detected by the temperature detector 24 is the second set temperature T 2 which is predetermined. (20 ° C. in this example).
【0040】そして、温度検知部24の検知温度が第2
の設定温度T2より低くなければ直ちにステップ5へ移
るが、低い場合にはステップ3でVR 補正処理及びVL
補正処理を行ない、ステップ4でフラグFragBを“1”
にした後、ステップ5でコピージョブがスタートしたか
(図示しないスタートキーが押下されたか)否かを判断
し、スタートするとステップ6で1枚目のコピー動作を
行なう。Then, the temperature detected by the temperature detector 24 is the second
If the temperature is not lower than the set temperature T2, the process immediately proceeds to step 5, but if it is lower than the set temperature T2, VR correction processing and VL are performed in step 3.
Perform correction processing and set flag FragB to "1" in step 4.
After that, it is determined in step 5 whether or not the copy job has started (whether or not a start key (not shown) is pressed), and if it starts, the copy operation for the first sheet is performed in step 6.
【0041】なお、上記のVR 補正処理及びVL 補正処
理時には、まず後述する補正ルールを参照し、温度検知
部24の検知温度に応じて帯電ローラ2への印加電圧の
補正を行なった後、前述したような各処理を行なう。こ
こで、図6の(a)(b)には感光体1の帯電電圧(表面電
圧)をそれぞれ−900V,−600Vにする場合の温
度検知部24の検知温度と帯電ローラ2への印加電圧の
補正量との関係を示しているが、その各関係を示すデー
タはそれぞれ補正テーブルとして制御装置31内のRO
Mに格納されている。At the time of the VR correction processing and the VL correction processing, the voltage applied to the charging roller 2 is corrected in accordance with the temperature detected by the temperature detecting section 24, after referring to the correction rule described later. Each processing as described above is performed. 6A and 6B, the detection temperature of the temperature detection unit 24 and the voltage applied to the charging roller 2 when the charging voltage (surface voltage) of the photoconductor 1 is -900V and -600V, respectively. Of the RO in the control device 31 as a correction table.
It is stored in M.
【0042】図4のフローに戻り、1枚目のコピー動作
が終了すると、ステップ7でコピージョブが終了したか
(設定コピー枚数に達したか)否かを判断し、まだであ
ればステップ6に戻って2枚目以降のコピー動作を行な
い、コピージョブが終了するとステップ8で図示しない
コピーカウンタを設定コピー枚数n分だけインクリメン
ト(+n)し、ステップ9でフラグFragAが“0”か否
かを判断する。このフラグFragAは、この複写機の使用
開始時には“0”に初期化されており、以後“1”にな
っても感光体が新たなものに交換される度に“0”に初
期化される。Returning to the flow of FIG. 4, when the copy operation for the first sheet is completed, it is determined in step 7 whether the copy job is completed (whether the set number of copies has been reached). The copy operation for the second and subsequent sheets is performed, and when the copy job ends, the copy counter (not shown) is incremented (+ n) by the set number of copies n in step 8, and whether the flag FragA is "0" in step 9 To judge. The flag FragA is initialized to "0" at the start of use of this copying machine, and is initialized to "0" every time the photoconductor is replaced with a new one even if it becomes "1" thereafter. .
【0043】そして、このフラグFragAが“0”なら
ば、ステップ10で感光体1の積算回転時間(図示しな
いルーチンで計測されるものとする)が予め定めた設定
時間t(例えば40時間)に達したか否かを判断して、
設定時間tに達した時にステップ11で帯電ローラのク
リーニングモードとなり、図3に示したクリーニング部
材27を帯電ローラ2に接触させてその表面をクリーニ
ングした後、帯電ローラ2から離間させる。それによっ
て、トナー等の汚れによる帯電不良(電位低下)が防止
される。If the flag FragA is "0", the cumulative rotation time of the photoconductor 1 (assumed to be measured by a routine not shown) at step 10 reaches a preset time t (for example, 40 hours). Judging whether or not it reached,
When the set time t is reached, in step 11, the charging roller cleaning mode is set, and the cleaning member 27 shown in FIG. 3 is brought into contact with the charging roller 2 to clean the surface thereof, and then separated from the charging roller 2. As a result, charging failure (potential drop) due to dirt such as toner is prevented.
【0044】次いで、ステップ12で温度検知部24の
検知温度に応じて帯電ローラ2への印加電圧を補正する
際に参照する補正ルールを上述した補正テーブルを用い
て切り換える。すなわち、この実施例ではVR補正処理
及びVL補正処理時の感光体の帯電電位を−900Vに
する必要があるため、帯電ローラ2への印加電圧を図6
の(a)の実線で示す補正ルールから破線で示す補正ル
ールに切り換える。Next, in step 12, the correction rule to be referred to when correcting the voltage applied to the charging roller 2 according to the temperature detected by the temperature detector 24 is switched using the above-mentioned correction table. That is, in this embodiment, it is necessary to set the charging potential of the photoconductor at the time of VR correction processing and VL correction processing to -900V, so the voltage applied to the charging roller 2 is as shown in FIG.
The correction rule indicated by the solid line in (a) is switched to the correction rule indicated by the broken line.
【0045】次いで、ステップ13でVR補正処理及び
VL補正処理を行なう。このとき、切り換えられた補正
ルールを参照し、温度検知部24の検知温度に応じて帯
電ローラ2への印加電圧の補正も行なう。その後、フラ
グFragAを“1”にして、以後ステップ11〜14の処
理を行なわないようにした後、ステップ5のコピージョ
ブがスタートしたか否かの判断に戻り、以後上述と同様
の処理を繰り返す。Next, at step 13, VR correction processing and VL correction processing are performed. At this time, referring to the switched correction rule, the voltage applied to the charging roller 2 is also corrected according to the temperature detected by the temperature detector 24. After that, the flag FragA is set to "1" so that the processes of steps 11 to 14 are not performed thereafter, and then the process returns to the determination of whether the copy job has started in step 5, and the same processes as described above are repeated thereafter. .
【0046】一方、ステップ9でフラグFragAが“0”
でないと判断されるか、あるいはステップ10で感光体
1の積算回転時間が予め定めた設定時間tに達していな
いと判断された場合には、図5のステップ15に移り、
温度検知部24の検知温度が予め定めた第1の設定温度
T1 (この例では18℃)より低いかどうかを判断す
る。On the other hand, in step 9, the flag FragA is "0".
If not, or if it is determined in step 10 that the cumulative rotation time of the photoconductor 1 has not reached the preset set time t, the process proceeds to step 15 in FIG.
It is determined whether the temperature detected by the temperature detector 24 is lower than a predetermined first set temperature T 1 (18 ° C. in this example).
【0047】そして、温度検知部24の検知温度が第1
の設定温度T1 より低くなければそのまま、低ければス
テップ16で帯電ローラのクリーニングモードとなって
上述と同様の処理を行なった後、ステップ17でフラグ
FragBが“1”か否かを判断し、“1”ならばステップ
18で温度検知部24の検知温度が第2の設定温度T2
以上あるか否かを判断する。Then, the temperature detected by the temperature detector 24 is the first
If the temperature is not lower than the set temperature T 1 of the above, if it is lower, the charging roller cleaning mode is set in step 16 and the same processing as described above is performed, and then the flag is set in step 17.
It is determined whether FragB is "1". If it is "1", the temperature detected by the temperature detector 24 is the second set temperature T 2 in step 18.
It is determined whether or not there is the above.
【0048】そして、温度検知部24の検知温度が第2
の設定温度T2 以上あれば、ステップ19でVR補正処
理及びVL補正処理を行なう。このとき、現在の補正ル
ールを参照し、温度検知部24の検知温度に応じて帯電
ローラ2への印加電圧の補正も行なう。次いで、ステッ
プ20でフラグFragBを“0”にし、ステップ21でコ
ピーカウンタを「0」にリセットした後、ステップ5へ
戻る。Then, the temperature detected by the temperature detecting section 24 is the second
If the temperature is equal to or higher than the set temperature T 2 of , VR correction processing and VL correction processing are performed in step 19. At this time, the current correction rule is referred to, and the voltage applied to the charging roller 2 is also corrected according to the temperature detected by the temperature detector 24. Next, the flag FragB is set to "0" in step 20, the copy counter is reset to "0" in step 21, and the process returns to step 5.
【0049】ステップ17でフラグFragBが“1”でな
いと判断されるか、あるいは温度検知部24の検知温度
が第2の設定温度T2 以上ないと判断された場合には、
ステップ22でコピーカウンタのカウント値(積算コピ
ー枚数)が予め設定されたコピー枚数N(例えば100
0枚)に達した否かを判断し、その設定コピー枚数Nに
達した時にのみステップ23で上述と同様にVR 補正処
理及びVL 補正処理を行ない、ステップ24でコピーカ
ウンタを「0」にリセットした後、ステップ5へ戻る。When it is determined in step 17 that the flag FragB is not "1" or the temperature detected by the temperature detector 24 is not equal to or higher than the second set temperature T 2 ,
In step 22, the count value of the copy counter (total number of copies) is set to a preset number of copies N (for example, 100).
(0 sheets) is determined, and only when the set number of copies N is reached, in step 23, VR correction processing and VL correction processing are performed as described above, and in step 24 the copy counter is reset to "0". After that, the process returns to step 5.
【0050】このように、この実施例の複写機において
は、コピージョブ(画像形成ジョブ)終了後に経時変化
検知装置33によって検知された経時変化量(感光体1
の積算回転時間)が予め定めた所定量(設定時間)を上
回った場合に、クリーニング部材27によって帯電ロー
ラ2をクリーニングし、帯電ローラ2への印加電圧を補
正する際に必要となる補正ルールを切り換えた後、前述
したVR補正処理及びVL補正処理を行ない、その補正結
果に基づいて以降のコピープロセスを行なうので、上記
補正ルールが切り換えられた直後でも感光体1表面の帯
電電位が変化することがなく、機内環境や経時変動に係
わらず感光体1の帯電電位は常に一定値に保たれ、安定
した画像品質を得られる。As described above, in the copying machine of this embodiment, the amount of change over time detected by the change-over-time detecting device 33 after the end of the copy job (image forming job) (photoreceptor 1
When the cumulative rotation time of the charging roller 2 exceeds a predetermined amount (setting time) set in advance, the cleaning member 27 cleans the charging roller 2 and a correction rule necessary for correcting the voltage applied to the charging roller 2 is set. After the switching, the VR correction processing and the VL correction processing described above are performed, and the subsequent copying process is performed based on the correction results. Therefore, the charging potential on the surface of the photoconductor 1 may change immediately after the correction rule is switched. In addition, the charging potential of the photoconductor 1 is always maintained at a constant value regardless of the environment inside the machine and the change over time, and stable image quality can be obtained.
【0051】また、温度検知部24の検知温度が予め定
めた閾値(設定温度T1 )を下回った場合に、クリーニ
ング部材27によって帯電ローラ2をクリーニングする
ので、以下の効果も得られる。すなわち、クリーニング
ユニット9によるクリーニング後の感光体1上にはわず
かにトナーが残っており、このトナーは主に自己の帯電
電荷の鏡像力によって感光体1上に付着しているため、
低温低湿でより数が増える傾向があるが、クリーニング
部材27によって帯電ローラ2をクリーニングすること
により、新たな機構によって機内環境を検知する必要が
なく、安価な構成で環境変動による帯電部材の汚れを効
果的に防止することができる。Further, when the temperature detected by the temperature detector 24 is below a predetermined threshold value (set temperature T 1 ), the cleaning member 27 cleans the charging roller 2, so that the following effects can be obtained. That is, a small amount of toner remains on the photoconductor 1 after cleaning by the cleaning unit 9, and the toner adheres to the photoconductor 1 mainly due to the image force of its own charge.
Although the number tends to increase due to low temperature and low humidity, by cleaning the charging roller 2 by the cleaning member 27, it is not necessary to detect the environment inside the apparatus by a new mechanism, and the charging member is not contaminated due to environmental changes with an inexpensive configuration. It can be effectively prevented.
【0052】さらに、温度検知部24の検知温度が予め
定めた閾値(設定温度T2 )を下回った場合にVR補正
処理及びVL補正処理を行なうので、以下の効果も得ら
れる。すなわち、感光体1の感度は低温時に低くなるた
め、図7に示すように必要な露光量が増大しその変化も
急峻になるが、もし露光量が高温時と変わらないとすれ
ば得られる画像は暗目にシフトしてしまう。しかし、上
述した各処理(露光量を増大させる処理を含んでいる)
を行なうことにより、低温時における感光体の感度の低
下によって画像が暗目にシフトすることを防止できる。Furthermore, since the VR correction processing and the VL correction processing are performed when the temperature detected by the temperature detection unit 24 falls below a predetermined threshold value (set temperature T 2 ), the following effects are also obtained. That is, since the sensitivity of the photoconductor 1 becomes low at low temperature, the required exposure amount increases and the change becomes sharp as shown in FIG. 7, but if the exposure amount does not change from that at high temperature, an image obtained Shifts to the dark. However, each processing described above (including processing for increasing the exposure amount)
By doing so, it is possible to prevent the image from shifting to the dark due to the decrease in the sensitivity of the photoconductor at a low temperature.
【0053】さらにまた、温度検知部24の検知温度が
予め定めた閾値(設定温度T2 )を下回った後その閾値
を上回った場合にもVR補正処理及びVL補正処理を行な
うので、機内環境の変化による画像の変動を防止するこ
ともできる。Furthermore, since the VR correction processing and the VL correction processing are performed even when the temperature detected by the temperature detection unit 24 falls below the threshold value (set temperature T 2 ) set in advance and then exceeds the threshold value, It is also possible to prevent the change of the image due to the change.
【0054】なお、この実施例におけるVR補正処理又
はVL補正処理では、感光体1の表面1aに形成した残
留電位パターン像又は基準電位パターン像のトナー付着
量をPセンサ8によって測定することにより残量電位又
は基準電位を検知するようにしたが、現像器4の手前に
感光体1の表面電位を測定する表面電位計を設け、それ
によって現像器4で可視像化される前の残留電位パター
ン又は基準電位パターンの電位、すなわち残量電位又は
基準電位を直接検知することもできる。In the VR correction processing or the VL correction processing in this embodiment, the amount of toner adhered to the residual potential pattern image or the reference potential pattern image formed on the surface 1a of the photoconductor 1 is measured by the P sensor 8 to leave the residual amount. Although the quantity potential or the reference potential is detected, a surface potential meter for measuring the surface potential of the photoconductor 1 is provided in front of the developing device 4, whereby the residual potential before being visualized by the developing device 4 is provided. It is also possible to directly detect the potential of the pattern or the reference potential pattern, that is, the remaining potential or the reference potential.
【0055】また、この実施例においては、図4及び図
5に示したように、所定の各タイミングでVR補正処理
とVL補正処理の両方を行なうようにしたが、VL 補正
処理のみを行なうようにしてもよい。それによって、セ
レン系の感光体を使用している場合には、上述と同様に
機内環境や経時変動に係わらずその感光体の帯電電位を
常に一定値に保つことができる。Further, in this embodiment, as shown in FIGS. 4 and 5, both the VR correction processing and the VL correction processing are carried out at predetermined timings, but only the VL correction processing is carried out. You may As a result, when a selenium-based photoconductor is used, the charge potential of the photoconductor can always be maintained at a constant value, regardless of the internal environment of the device and the temporal change, as described above.
【0056】以上、この発明を複写機に適用した実施例
について説明したが、この発明はこれに限らず、レーザ
プリンタ,LEDプリンタ,液晶シャッタプリンタ等の
光プリンタやファクシミリ装置等の他の静電写真方式の
画像形成装置にも適用可能である。Although the embodiment in which the present invention is applied to a copying machine has been described above, the present invention is not limited to this, and other electrostatic printers such as laser printers, LED printers, liquid crystal shutter printers, and facsimile machines. It is also applicable to a photographic image forming apparatus.
【0057】[0057]
【発明の効果】以上説明してきたように、この発明の画
像形成装置によれば、機内環境(使用環境)や経時変動
に係わらず感光体の帯電電位を常に一定値に保つことが
でき、安定した画像品質を得ることができる。請求項4
の発明によれば、帯電部材がトナーで汚れることもなく
なるため帯電不良が低減し、より安定した画像品質を得
られる。As described above, according to the image forming apparatus of the present invention, the charging potential of the photoconductor can be constantly maintained at a constant value regardless of the internal environment (usage environment) and the temporal change. The obtained image quality can be obtained. Claim 4
According to the invention, since the charging member is not contaminated with the toner, charging failure is reduced and more stable image quality can be obtained.
【0058】請求項5の発明によれば、新たな機構を設
けて機内環境を検知する必要もなくなるため、安価な構
成で環境変動による帯電部材の汚れを効果的に防止する
ことができる。請求項6の発明によれば、低温時におけ
る感光体の感度の低下によって画像が暗目にシフトする
のを防止することもできる。請求項7の発明によれば、
機内環境の変化による画像の変動を防止することもでき
る。According to the fifth aspect of the present invention, it is not necessary to provide a new mechanism to detect the environment inside the machine. Therefore, it is possible to effectively prevent the charging member from being contaminated due to environmental changes with an inexpensive structure. According to the sixth aspect of the invention, it is possible to prevent the image from shifting to the dark due to the decrease in the sensitivity of the photoconductor at a low temperature. According to the invention of claim 7,
It is also possible to prevent a change in the image due to a change in the environment inside the machine.
【図1】この発明の基本構成を示す機能ブロック図であ
る。FIG. 1 is a functional block diagram showing a basic configuration of the present invention.
【図2】この発明の一実施例である複写機のドラム回り
を示す概略構成図である。FIG. 2 is a schematic configuration diagram showing around a drum of a copying machine which is an embodiment of the present invention.
【図3】その主要部分を制御系と共に示す図である。FIG. 3 is a diagram showing the main part together with a control system.
【図4】図3の制御装置によるこの発明に係わる処理を
示すフロー図である。FIG. 4 is a flowchart showing a process according to the present invention by the control device of FIG.
【図5】その処理の続きを示すフロー図である。FIG. 5 is a flowchart showing a continuation of the processing.
【図6】図2に示した感光体の表面電圧をそれぞれ−9
00V及び−600Vにする場合の温度検知部の検知温
度と帯電ローラ2への印加電圧の補正量との関係を示す
線図である。FIG. 6 shows a surface voltage of the photoconductor shown in FIG.
6 is a diagram showing the relationship between the temperature detected by the temperature detection unit and the correction amount of the voltage applied to the charging roller 2 when the voltage is set to 00 V and −600 V. FIG.
【図7】図2に示した感光体の温度と必要露光量との関
係を示す線図である。FIG. 7 is a diagram showing the relationship between the temperature of the photoconductor shown in FIG. 2 and the required exposure amount.
1:感光体 2:帯電ローラ 3:イレーサ 4:現像器 7:転写装置 8:Pセンサ 9:クリーニングユニット 10:クエンチングランプ 11:露光装置 12:レジストローラ 13:加圧ローラ 14:トナー補給装置 21:導電性芯金 22:弾性層 23:表面層 24:温度検知部 25:導電性板バネ 26:温度検知素子 27:クリーニング部材 31:制御装置 32:電圧印加装置 33:経時変化検知装置 A:温度検知手段 B:経時変化検知手段 C:印加電圧補正手段 D:補正ルール切換手段 E:光量補正手段 F:電位補正手段 1: Photoconductor 2: Charging roller 3: Eraser 4: Developing device 7: Transfer device 8: P sensor 9: Cleaning unit 10: Quenching lamp 11: Exposure device 12: Registration roller 13: Pressure roller 14: Toner supply device 21: Conductive core bar 22: Elastic layer 23: Surface layer 24: Temperature detection part 25: Conductive leaf spring 26: Temperature detection element 27: Cleaning member 31: Control device 32: Voltage application device 33: Temporal change detection device A : Temperature detecting means B: Aging change detecting means C: Applied voltage correcting means D: Correction rule switching means E: Light quantity correcting means F: Potential correcting means
Claims (7)
その表面を一様に帯電させる帯電部材と、該帯電部材に
よって帯電された前記感光体の表面を露光して静電潜像
を形成する露光装置と、その潜像を現像ローラによりト
ナーを付着させて顕像化する現像器と、その顕像化され
たトナー像を転写紙に転写する転写装置と、前記帯電部
材の表面をクリーニングするクリーニング部材とを備え
た静電写真方式の画像形成装置において、 前記帯電部材の温度を検知する温度検知手段と、前記感
光体の経時変化を検知する経時変化検知手段と、前記温
度検知手段の検知温度に応じて前記帯電部材への印加電
圧を補正する印加電圧補正手段と、該手段による前記検
知温度に応じた印加電圧の補正ルールを前記経時変化検
知手段によって検知された経時変化量に応じて切り換え
る補正ルール切換手段と、前記印加電圧補正手段によっ
て補正した電圧を前記帯電部材に印加することにより前
記感光体の表面を帯電した後、前記露光装置によって露
光して基準電位パターンを形成し、その電位を検知して
作像プロセス時の前記露光装置の光量を補正する光量補
正手段とを設けたことを特徴とする画像形成装置。1. A rotating photoconductor, a charging member that comes into contact with the photoconductor to uniformly charge the surface thereof, and an electrostatic latent image formed by exposing the surface of the photoconductor charged by the charging member. An exposure device that forms an image, a developing device that visualizes the latent image by adhering toner to the latent image with a developing roller, a transfer device that transfers the visualized toner image onto a transfer paper, and a charging member In an electrostatographic image forming apparatus including a cleaning member for cleaning a surface, a temperature detecting unit that detects a temperature of the charging member, a time change detecting unit that detects a time change of the photoconductor, and the temperature The applied voltage correction means for correcting the applied voltage to the charging member according to the detection temperature of the detection means, and the correction rule of the applied voltage according to the detection temperature by the means are provided for the lapse of time detected by the aging change detection means. Correction rule switching means for switching in accordance with the charge amount, and a voltage corrected by the applied voltage correction means is applied to the charging member to charge the surface of the photoconductor, and then exposed by the exposure device to expose a reference potential pattern. And a light amount correction means for detecting the potential and correcting the light amount of the exposure device during the image forming process.
前記印加電圧補正手段によって補正した電圧を前記帯電
部材に印加することにより前記感光体の表面を帯電した
後除電し、その残留電位を検知して作像プロセス時の前
記感光体表面の帯電電位あるいは前記現像ローラの現像
バイアスを補正する電位補正手段を設けたことを特徴と
する画像形成装置。2. The image forming apparatus according to claim 1,
By applying the voltage corrected by the applied voltage correction means to the charging member, the surface of the photoconductor is charged and then discharged, and the residual potential is detected to detect the charging potential of the surface of the photoconductor during the image forming process. An image forming apparatus comprising: a potential correcting unit that corrects a developing bias of the developing roller.
ョブ終了後に前記経時変化検知手段によって検知された
経時変化量が予め定めた所定量を上回った場合に、前記
印加電圧補正手段による前記検知温度に応じた印加電圧
の補正ルールを切り換える手段であり、前記印加電圧補
正手段が、前記補正ルール切換手段による補正ルールの
切り換えが行なわれた後、該補正ルールを参照して前記
温度検知手段の検知温度に応じて前記帯電部材への印加
電圧を補正する手段であることを特徴とする請求項1又
は2記載の画像形成装置。3. The temperature detected by the applied voltage correction means when the correction rule switching means has a time-dependent change amount detected by the time-dependent change detecting means after the image forming job is over, exceeds a predetermined amount. Means for switching the correction rule of the applied voltage according to the above, and the applied voltage correction means detects the temperature detection means by referring to the correction rule after the correction rule is switched by the correction rule switching means. The image forming apparatus according to claim 1, wherein the image forming apparatus is a unit that corrects a voltage applied to the charging member according to temperature.
前記光量補正手段及び前記電位補正手段による補正処理
が行なわれる前に、前記クリーニング部材によって前記
帯電部材をクリーニングする手段を設けたことを特徴と
する画像形成装置。4. The image forming apparatus according to claim 2,
An image forming apparatus, comprising means for cleaning the charging member with the cleaning member before the correction processing by the light amount correction means and the potential correction means is performed.
画像形成装置において、前記温度検知手段の検知温度が
予め定めた閾値を下回った場合に、前記クリーニング部
材によって前記帯電部材をクリーニングする手段を設け
たことを特徴とする画像形成装置。5. The image forming apparatus according to claim 1, wherein the cleaning member cleans the charging member when the temperature detected by the temperature detecting unit falls below a predetermined threshold value. An image forming apparatus comprising:
が、前記温度検知手段の検知温度が予め定めた閾値を下
回った場合に前記補正処理を行なう手段であることを特
徴とする請求項2又は4記載の画像形成装置。6. The light amount correction means and the potential correction means are means for performing the correction processing when the temperature detected by the temperature detection means falls below a predetermined threshold value. 4. The image forming apparatus according to item 4.
が、前記温度検知手段の検知温度が予め定めた閾値を下
回った後該閾値を上回った場合に前記補正処理を行なう
手段であることを特徴とする請求項2又は4記載の画像
形成装置。7. The light quantity correction means and the potential correction means are means for performing the correction processing when the temperature detected by the temperature detection means falls below a predetermined threshold value and then exceeds the threshold value. The image forming apparatus according to claim 2 or 4.
Priority Applications (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP6233121A JPH0895317A (en) | 1994-09-28 | 1994-09-28 | Image forming device |
US08/535,817 US5966558A (en) | 1994-09-28 | 1995-09-28 | Image forming apparatus having control of exposure and charging depending on detected temperature |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP6233121A JPH0895317A (en) | 1994-09-28 | 1994-09-28 | Image forming device |
Publications (1)
Publication Number | Publication Date |
---|---|
JPH0895317A true JPH0895317A (en) | 1996-04-12 |
Family
ID=16950094
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
JP6233121A Pending JPH0895317A (en) | 1994-09-28 | 1994-09-28 | Image forming device |
Country Status (2)
Country | Link |
---|---|
US (1) | US5966558A (en) |
JP (1) | JPH0895317A (en) |
Cited By (4)
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JP2008070836A (en) * | 2006-09-15 | 2008-03-27 | Ricoh Co Ltd | Cleaning device and cleaning method for electrifying roller |
US8019239B2 (en) | 2008-11-25 | 2011-09-13 | Ricoh Company, Limited | Device and method for detecting life of organic photoreceptor and image forming apparatus |
JP2018060086A (en) * | 2016-10-06 | 2018-04-12 | キヤノン株式会社 | Image forming apparatus |
CN109541909A (en) * | 2017-09-21 | 2019-03-29 | 柯尼卡美能达株式会社 | The control method of image forming apparatus and image forming apparatus |
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JP3388178B2 (en) * | 1998-04-20 | 2003-03-17 | 京セラミタ株式会社 | Laser intensity adjustment method |
DE19859093A1 (en) * | 1998-12-21 | 2000-07-27 | Oce Printing Systems Gmbh | Process for improved electrographic printing of image details and printing device operating according to this process |
US6463226B2 (en) * | 2000-03-29 | 2002-10-08 | Canon Kabushiki Kaisha | Image forming apparatus which corrects image forming conditions in low-temperature environment and at continuous image formation |
JP2001312124A (en) * | 2000-05-02 | 2001-11-09 | Ricoh Co Ltd | Image forming device |
JP2002049225A (en) * | 2000-07-31 | 2002-02-15 | Canon Inc | Electrophotographic image forming device and process cartridge |
JP2002278176A (en) * | 2001-03-14 | 2002-09-27 | Canon Inc | Image forming device |
JP4323836B2 (en) * | 2003-03-07 | 2009-09-02 | キヤノン株式会社 | Image forming apparatus |
JP2008015170A (en) * | 2006-07-05 | 2008-01-24 | Brother Ind Ltd | Image forming apparatus |
Family Cites Families (13)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
DE3470968D1 (en) * | 1984-02-28 | 1988-06-09 | Agfa Gevaert Nv | Improvements relating to the production of developed electrostatic images |
JPS6172268A (en) * | 1984-09-17 | 1986-04-14 | Konishiroku Photo Ind Co Ltd | Electrostatic recording device |
US4870460A (en) * | 1986-12-05 | 1989-09-26 | Ricoh Company, Ltd. | Method of controlling surface potential of photoconductive element |
JPS63142371A (en) * | 1986-12-05 | 1988-06-14 | Toshiba Corp | Image forming device |
JPH0434563A (en) * | 1990-05-31 | 1992-02-05 | Toshiba Corp | Image forming device |
JPH04270356A (en) * | 1990-08-10 | 1992-09-25 | Ricoh Co Ltd | Image forming device |
JPH04186381A (en) * | 1990-11-21 | 1992-07-03 | Ricoh Co Ltd | Contact charging apparatus |
JP3266297B2 (en) * | 1991-03-20 | 2002-03-18 | 株式会社リコー | Electrophotographic process control equipment |
JPH04316064A (en) * | 1991-04-16 | 1992-11-06 | Ricoh Co Ltd | Contact electrostatic charging device |
JPH05241428A (en) * | 1992-03-02 | 1993-09-21 | Sharp Corp | Electrophotographic device |
JPH06186803A (en) * | 1992-12-18 | 1994-07-08 | Canon Inc | Image forming device |
JPH06230642A (en) * | 1993-02-02 | 1994-08-19 | Fuji Xerox Co Ltd | Potential controller for photosensitive body |
US5606399A (en) * | 1994-09-28 | 1997-02-25 | Ricoh Company, Ltd. | Device for correcting an applied voltage in an image forming apparatus |
-
1994
- 1994-09-28 JP JP6233121A patent/JPH0895317A/en active Pending
-
1995
- 1995-09-28 US US08/535,817 patent/US5966558A/en not_active Expired - Fee Related
Cited By (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP2008070836A (en) * | 2006-09-15 | 2008-03-27 | Ricoh Co Ltd | Cleaning device and cleaning method for electrifying roller |
US8019239B2 (en) | 2008-11-25 | 2011-09-13 | Ricoh Company, Limited | Device and method for detecting life of organic photoreceptor and image forming apparatus |
JP2018060086A (en) * | 2016-10-06 | 2018-04-12 | キヤノン株式会社 | Image forming apparatus |
CN109541909A (en) * | 2017-09-21 | 2019-03-29 | 柯尼卡美能达株式会社 | The control method of image forming apparatus and image forming apparatus |
CN109541909B (en) * | 2017-09-21 | 2022-02-25 | 柯尼卡美能达株式会社 | Image forming apparatus and method of controlling image forming apparatus |
Also Published As
Publication number | Publication date |
---|---|
US5966558A (en) | 1999-10-12 |
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